A power generation system includes a power module and an external process module. The external process module may include at least one engine support element. The power module has at least one connection zone, and the external process module has at least one connection zone that is configured to align with the at least one connection zone of the power module. The aligned connection zones of the power module and the external process module permit relatively quick and inexpensive attachment of the external process module to the power module. The at least one engine support element may be an aftertreatment element.